This application represents the third competitive renewal for our T32 program Training in HIV Pathogenesis. The program supports 6 predoctoral and 3 postdoctoral trainees per year. The program is based at the Perelman School of Medicine at the University of Pennsylvania, the University of Pennsylvania School of Dental Medicine and the Wistar Institute, which occupy a single, contiguous campus in Philadelphia. Together, these institutions have one of the largest HIV/AIDS research programs in the country, with a funding base of >$40 million as determined by the NIH Office of AIDS Research. Closely associated with our training program is our Center for AIDS Research (CFAR) which was renewed in 2014 (i.e. $2.25 million annually), thereby supporting numerous programs that benefit our trainees. Among the many individuals who study HIV/AIDS on our campus, a select group of 17 mentors are associated with this T32 program. In our program, we place special emphasis on collaborative science and a commitment to training students and postdoctoral fellows. The cohesive nature of our training program is demonstrated by the fact that fully 16 of the 17 trainers have published papers with other trainers, that 11 of the trainers share jointly funded NIH grants with other trainers (a total of 11 funded grants, not counting the CFAR grant), 23 of our trainees have published with 2 or more trainers, that there are many joint lab meetings, and that our trainers participate in extensive programmatic activities and minority-recruitment efforts. Over the last 10 years the program has supported 40 predoctoral trainees who worked in 19 different laboratories. Currently, one is an Assistant Professor working on HIV, 1 is a staff scientist at NCI, 9 are now doing postdocs at distinguished universities such as Harvard, Penn, Oxford, UCSF, UCSD, and Tufts, 16 are still in training, 1 just graduated and is looking for a postdoc, 3 with MD/PHD backgrounds are continuing clinical training, 2 are biotech business consultants, 2 are staff scientists in industry, 1 is taking time off to raise twins, 1 isan IP attorney and 1 left for health reasons. Over the last 10 years the program has supported 18 postdoctoral trainees who have worked in 12 laboratories. Currently 1 is an Associate Professor working on HIV, 1 is a Research Assistant Professor, 1 is a director at the AERAS Foundation, 1 is a scientist in industry, 1 is a consultant, 6 are still in training, 3 are technical writer/edtors, 1 works in tech transfer, 1 is unknown, 2 are staff scientists. Many of our trainees are stepping into leadership roles--one leads a TB vaccine program at the AERAS Foundation, another is Chief of the Viral Pathogenesis Section in the Laboratory of Viral Diseases at NIAID, a third founded her own laboratory at Duquesne studying infection and neurotoxicity, a fourth founded her own laboratory working on HIV at Eastern University and was recently appointed to Associate Professor, and a fifth just founded her own laboratory at the University of Washington focused on HIV and SIV research. Based on these outcomes we feel we are training young scientists effectively, and so propose to maintain the training program at the present size.